Merkel cell carcinoma (MCC) is a rare and aggressive cutaneous neuroendocrine neoplasm with a poor prognosis. It usually affects white-skinned old individuals in areas chronically exposed to solar radiation. MCC's spontaneous regression is a mechanism not yet clearly understood. It is a known fact and a rare occurrence in MCC, after biopsy or incomplete resection has been performed. Considering the rarity of this type of occurrence, we will describe a clinical case treated at Hospital da Baleia, Belo Horizonte, State of Minas Gerais, Brazil. The report will address a male patient, 72 years old, leukodermic, with systemic arterial hypertension, type 2 diabetes mellitus and vitiligo. He was referred to the surgery department with a lesion in the right hypothenar region with an onset 4 months before admission, and presented with tumor regression after biopsy. Data was assembled through the analysis of the patient's medical record, after declared authorization, open interview with the patient at the time of follow-up appointments to the hospital's outpatient clinic, and analysis of photographic records of the injury before and after the instituted therapy.